WO2012131326A2

WO2012131326A2 - Dynamic finger fixator

Info

Publication number: WO2012131326A2
Application number: PCT/GB2012/050605
Authority: WO
Inventors: Simon Halsey; Tim ADLAM
Original assignee: Bath Institute Of Medical Engineering
Priority date: 2011-03-30
Filing date: 2012-03-20
Publication date: 2012-10-04
Also published as: GB2489471A; GB201115299D0; WO2012131326A3; GB201105304D0; GB2484178A; GB2484178B

Abstract

A dynamic finger fixator (10) comprises a two-part elongate strut element (12) and two pin-engagable elements (14) spaced apart on the two-part elongate strut element (12). The two-part elongate strut element (12) includes spacing-adjustment means (16) for selectively adjusting and setting a spacing between the two pin-engagable elements (14). Preferably, a first said part of the strut element includes a strut member (20), and a second said part includes a rotatable adjuster (32) forming at least part of the spacing- adjustment means (16) rotatably mounted on the strut member (20). The strut member (20) includes a first said pin engagable element (14) and the rotatable adjuster (32) includes a second said pin engagable element (14, 34) which is off-centre on the rotatable adjuster (32), so that dynamic fixation is impartable to a patient's finger.

Description

Dynamic Finger Fixator

The present invention relates to a dynamic finger fixator for holding a broken, fractured or damaged finger during the healing process.

A damaged or fractured finger can be treated in various ways including early mobilisation (movement), splintage and stabilisation surgically. The latter can include stabilisation with K wires, screws or screws and plates. For difficult fractures especially comminuted (multi- fragmented) fractures, particularly into a joint, then an external frame may be the only satisfactory solution. The frame is typically fixed to the injured bones proximal and distal to the fracture. Some form of external apparatus acts to distract the K wires, which forces then act against the natural tension forces of the soft tissues. This allows for realignment of the fracture fragments. For intra-articular fractures (into the joint) early movement helps to optimise recovery both of the joint and the soft tissues. At present the distraction force across the fracture is judged by experience. The external frames used at present are either technically demanding to apply or adjust, or bulky; limiting their use especially to border digits.

The present invention seeks to provide a solution to these problems, whereby a separating force can be applied across a damaged area of a finger and the separating force can be easily adjusted as necessity dictates. Joint mobility is maintained during the recovery period due to the arrangement which facilitates dynamic fixation, thereby accelerating a return to a fully- functioning joint.

According to a first aspect of the invention, there is provided a dynamic finger fixator comprising a two-part elongate strut element and two pin engagable elements spaced apart on the two-part elongate strut element, the two-part elongate strut element including spacing-adjustment means for selectively adjusting and setting a spacing between the two pin engagable elements.

Preferable and/or optional features of the first part of the invention are set forth in claims 2 to 40, inclusive. According to a second aspect of the invention, there is provided a dynamic finger fixator comprising a two-part elongate strut element and two pin engagable elements spaced apart on the two-part elongate strut element, the two-part elongate strut element including spacing-adjustment means for selectively adjusting and setting a spacing between the two pin engagable elements in situ, a first said part of the strut element including a strut member, and a second said part being or including a rotatable adjuster forming at least part of the spacing-adjustment means, the strut member including a first said pin engagable element and the rotatable adjuster including a second said pin engagable element which is off-centre on the rotatable adjuster, so that dynamic fixation is impartable to a patient's finger.

Preferable and/or optional features of the second aspect of the invention are set forth in claims 42 to 58, inclusive.

The invention will now be more particularly described, by way of examples only, with reference to the accompanying drawings, in which :

Figure 1 shows a first embodiment of an in use dynamic finger fixator, in accordance with the present invention;

Figure 2 shows a rotation tool being used to angularly adjust a rotatable adjuster of the dynamic finger fixator in situ;

Figure 3 shows a perspective exploded view of a second embodiment of a dynamic finger fixator, in accordance with the present invention;

Figure 4 shows a plan exploded view of the dynamic finger fixator of Figure 3;

Figure 5 shows the dynamic finger fixator of Figure 3 when located on a patient's finger; and

Figure 6 shows a perspective view of a third embodiment of a dynamic finger fixator, in accordance with the present invention and shown located on a patient's finger. Referring firstly to Figures 1 and 2 of the drawings, there is shown a first embodiment of a dynamic finger fixator 10 which comprises a two-part elongate strut element 12, two pin-engagable elements 14, a spacing-adjustment mechanism 16, and first and second resiliently flexible pin elements 18. A first part of the strut element 12, which in this case is formed of moulded plastics or surgical-grade metal, preferably includes a rectilinear planar or substantially planar elongate strut member 20 having a body 22 providing an enlarged head end 24 and a tail end 26 opposite the head end 24. A first one of the pin-engagable elements 14 is provided at or adjacent to the tail end 26 and extends at least partway, and in this case a majority of the way, along a longitudinal extent of the body 22 of the strut member 20.

The first pin-engagable element 14 in this embodiment is a plurality of spaced-apart tail apertures 28 which extend through the body 22. The tail apertures 28 are spread apart laterally, for example, by providing a plurality of adjacent staggered or offset rows, over the body 22 as well as longitudinally from the tail end 26.

An axis of the bore of each tail aperture 28 is preferably normal or substantially normal to the longitudinal extent of the body 22.

The head end 24 of the body 22 is enlarged relative to the tail end 26, and includes a single large head aperture 30, in this case being circular, therethrough. The head aperture 30 is adapted to receive the second part of the strut element 12, being a rotatable adjuster 32. The rotatable adjuster 32 is a circular disk dimensioned to form a tight factional fit within the head aperture 30. The walls of the head aperture 30 and the rotatable adjuster 32 are cylindrical or substantially cylindrical, but may be tapering to form a Morse taper-fit, for example. Other engagement means may also be considered, for example, by including a circumferentially extending ridge and channel partway along the lateral extents of the walls of the head aperture 30 and the rotatable adjuster 32, whereby a push- fit positive engagement is achievable.

Furthermore, although in this embodiment the walls of the head aperture 30 and the rotatable adjuster 32 are smoothly continuous, they may include indexing means, such as low rise teeth, again to prevent or limit unintentional relative angular displacement. The low rise teeth are preferably of a height that allows rotation of the rotatable adjuster 32 whilst within the head aperture 30, rather than requiring extraction and re-insertion.

Other modifications are also possible. For example, the head aperture 30 and the rotatable adjuster 32 may be non-circular. In this case, complementarily-shaped lugs may be formed into the walls to enable indexing.

The spacing-adjustment mechanism 16 makes use of the rotatable adjuster 32 and a second one of the pin-engagable elements 14 which includes a plurality of secondary head apertures 34 through the rotatable adjuster 32. The secondary head apertures 34 extend in parallel with the tail apertures 28.

The secondary head apertures 34 are radially spaced from a rotational axis of the rotatable adjuster 32, and in this embodiment, the secondary head apertures 34 are equi- angularly spaced apart from each other. Additionally or alternatively, the secondary head apertures may be equi-radially spaced from a centre of rotation of the adjuster 32, or they may be or include non-uniformly radially spaced secondary head apertures for fine adjustment. For example, there may be more than one aperture aligned in a radial direction of the secondary head aperture.

The tail apertures 28 and the secondary head apertures 34 are dimensioned to receive as a close fit the pin elements 18 mentioned above.

In use, the first pin element 18, typically being Kirschner wire, K-wire or other sterilised sharpened smooth stainless steel, titanium or other biocompatible material pin, is inserted through the patient's finger 36 so that the bone is engaged to one side of the damaged area. The second pin element 18, again typically being Kirschner wire, K-wire or other sterilised sharpened smooth stainless steel, titanium or other biocompatible material pin, is inserted through the patient's finger 36 so that the bone is engaged to the other side of the damaged area. In the case of a damaged phalange or more specifically a damaged phalanx, the first pin element 18 is preferably inserted at or adjacent to the centre of rotation of the interphalangeal joint proximal of the damaged area, and the second pin element 18 is inserted through the phalanx adjacent to and distal of the damaged area. A first strut element 12 is then located on the first and second pin elements 18 on one side of the finger 36, whereby the first pin element 18 is inserted into an appropriate one of the secondary head apertures 34, and the second pin element 18 is inserted into an appropriate one of the tail apertures 28. Preferably, the first and second pin elements 18, being resiliently flexible, are biased slightly away from each other by the strut element 12 by the engagement with the secondary head aperture 34 and the tail aperture 28.

A second strut element 12 is also located on the first and second pin elements 18 on the other side of the finger, in the same manner as the first strut element 12. The first and second pin elements 18 may be deformed, such as by bending, to lock the strut elements 12 in place to the finger 36, and the two strut elements 12 are interengaged around the finger 36 using surgical tape, plaster or other suitable binding.

A surgical rotation tool 38 is then used to rotate the rotatable adjuster 32 in situ to further bias the first and second resiliently flexible pin elements 18 away from each other. The rotation tool 38 preferably comprises a fixed head 40 and an elongate handle 42. The head 40 includes at least two spaced-apart pins 44 which are receivable in at least two of the unoccupied secondary head apertures 34. The pins 44 extend at or substantially at right angles to the handle 42. By turning the handle 42, the pins 44 cause the rotatable adjuster 32 to turn, thereby dynamically adjusting the tension imparted to the first and second pin elements 18.

Although two spaced-apart pins 44 are suggested, the head 40 of the rotation tool 38 may utilise a single non-circular pin if the secondary head apertures 34 are non-circular, or may utilise openings if engagement pins are provided on the rotatable adjuster 32 instead. More than two spaced-apart pins can also be considered.

Consequently, as the healing process progresses, the rotation tool 38 can be used periodically on the rotatable adjuster 32 of both strut elements 12 to adjust the tension across the damaged area, thereby promoting a more uniform repair and reducing the build up of fracture callus. Referring now to Figure 3 and Figure 4 of the drawings, there is shown a second embodiment of a dynamic finger fixator. Like references refer to parts which are similar to those of the first embodiment, and therefore further detailed description is omitted.

The finger fixator 10 of this embodiment comprises a two-part elongate strut element 12, two pin-engagable elements 14, a spacing-adjustment mechanism 16, and first and second pin elements which in this case are not shown but which are identical to those described above.

The strut element 12 includes similarly shaped first and second rigid strut members 20, generally being formed from biocompatible plastics or metal. Each strut member 20 is planar or substantially planar and includes a body 22 having a head 46 and two-spaced apart legs 48 which extend from the head 46. The legs 48 are parallel with each other, and are preferably interengaged via a cross-member 50 extending laterally therebetween partway along their longitudinal extents.

The two strut members 20 are abutable on their inner faces 52, and these inner faces 52 include the spacing-adjustment mechanism 16 which in this case comprises opposing sets of interengagable teeth 54. The teeth 54 extend continuously over the inner faces 52 of the strut members 20. However, it is possible that the teeth 54 may only need to be provided on the legs 48, and in this case, the teeth 54 may only need to be provided on one leg 48.

To provide a ratchet interface, the teeth 54 are preferably angled to face towards the free distal ends 56 of the legs 48 and thus away from the head 46. This thus simplifies adjustment by allowing the two strut members 20 to slide more easily apart whilst reducing the likelihood of the heads 46 moving back towards each other.

By spacing the legs 48 apart, a closed ended channel 58 is formed therebetween, being closed at the one end by the head 46 and at the other end by the cross-member 50. The head 46 and the cross-member 50 thus effectively act as stops.

An open end channel 60 is also formed between the spaced-apart legs 48, being closed at the one end by the cross-member 50 and open at the other distal end 56 of the legs 48. The spacing-adjustment mechanism 16 further includes a fastener 62 for releasably fastening the two strut members 20 together, so that the teeth 54 interdigitate or interengage. The fastener 62 preferably extends through the closed ended channels 58, thereby utilising the head and cross-member ends as stops if needs be. However, the fastener 62 can be inserted through the open end channels 60, or a combination of the open end channel 60 and the closed ended channel 58, as necessity dictates.

To enable a head 64 and tail 66 of the fastener 62 to be preferably recessed flush with outer surfaces 68 of the strut members 20, inner walls of the legs 48 are stepped to provide recessed flats 70 for the fastener 62 to seat on.

The fastener 62 is typically a surgical screw-threaded bolt and nut, but other types of fastener 62 may be considered. For example, the interior surfaces of the legs 48 may be fluted to enable the nut to be dispensed with.

Furthermore, the fastener may be a rotatable click-lock mechanism whereby rotation in one direction enables the strut members 20 to be extended relative to each other, and rotation in the other direction enables the strut members 20 to be retracted relative to each other.

One said pin-engagable element 14 is provided in the head 46 of each strut member 20, and as in the first embodiment, this is a pin-receivable aperture 72 dimensioned to receive the pin element 18. In this case, only a single pin-receivable aperture 72 is provided. However, one or both pin-engagable elements 14 may include more than one pin-receivable aperture 72.

Usage of the finger fixator 10 of the second embodiment is very similar to that of the first embodiment, and therefore this description is not repeated here. With the finger fixator 10 in place on a user's finger 36, adjustment is achieved by loosening the fastener 62 and sliding the two strut members 20 apart whereby the opposing teeth 54 ride over each other in a ratchet fashion. Once suitable tension has been imparted to the two resiliently flexible pin elements 18 passing through the patient's finger 36 either side of the damaged area, the fastener 62 is retightened to maintain the imparted tension. Referring now to Figure 6 of the drawings, there is shown a third embodiment of a finger fixator. Like references again refer to parts which are similar to those of the first and second embodiment, at least in terms of function, and therefore further detailed description is omitted.

The finger fixator 10 of this embodiment again comprises a two-part elongate strut element 12, two pin-engagable elements 14, a spacing-adjustment mechanism 16, and first and second pin elements 18 which in this case are not shown.

The strut element 12 includes similarly shaped first and second rigid strut members 20, generally being formed from biocompatible plastics or metal. Each strut member 20 includes an elongate, preferably planar or substantially planar, rectilinear body 22 having a head end 74 and a tail end 76. A saddle member 78 extends perpendicularly or substantially perpendicularly from the tail end 76 to provide two arms 80 which are spaced apart to receive a patient's finger 36.

Each arm 80 extends laterally of the body 22 and is at least in part arcuate. A said pin- engagable element 14 is provided at or adjacent to the free distal ends 82 of the arms 80 of the saddle member 78. In this case, each pin-engagable element 14 includes two pin- receivable apertures 72 dimensioned to receive the respective pin element 18 as a close sliding fit. One said pin-receivable aperture 72 is provided in each arm 80 of the saddle member 78, laterally of the body 22. However, more than one pin-receivable aperture 72 can be included, again as necessity dictates.

The spacing-adjustment mechanism 16 comprises an elongate key formed in the longitudinal direction on one body 22 of one of the strut members 20, and a complementarily shaped keyway slot formed longitudinally on the body 22 of the other strut member 20. A re leasable fastener, which is not shown in this case but being similar to that of the second embodiment, is also preferably included to maintain the set positions of the two strut members 20 relative to each other.

The key and keyway slot beneficially prevent or limit relative angular displacement of the two strut members 20. However, other means for adjusting a spacing between the pin-engagable elements 14 on the strut element 12 can be considered, such as only using a releasable fastener, or using a sliding ratchet mechanism.

Usage of the finger fixator 10 of the third embodiment is very similar to that of the first and second embodiments, and therefore further description is again dispensed with. With the finger fixator 10 in place on a user's finger 36, the bodies 22 of the two strut members 20 form an adjustable spine along the outer longitudinal portion of the finger 36. Adjustment is achieved by loosening the fastener and sliding the two strut members 20 apart, whereby the saddle members 78 become further separated from each other. Once suitable tension has been imparted to the two resiliently flexible pin elements 18 passing through the patient's finger 36 either side of the damaged area, the fastener is retightened to maintain the imparted tension.

Although the bodies of the two strut elements at least in part overlie each other, they may be telescopically extendable and retractable relative to each other. Other length adjustment means for adjusting an extended length of the strut element may also be considered.

Furthermore, instead of or in addition to the key and keyway, teeth may be utilised similarly to the second embodiment to form a ratchet-like engagement between the two bodies of the strut members.

It may be feasible to combine parts of two or more of the embodiments described above. For example, the rotatable adjuster of the first embodiment could be incorporated into the head of the second embodiment.

The rotatable adjuster may be a domed disk having a convex upper and/or lower surface. The main aperture would therefore preferably have a complementarily shaped wall being concave across the lateral extent to more securely retain the rotatable adjuster in place as a press-fit. Conversely, the domed disk may have a concave upper and/or lower surface with the complementarily shaped wall being convex.

Although the pin elements are bent over at their distal ends to engage with the strut element and the rotatable adjuster, other means for capping or engaging the pin elements with the strut element and the rotatable adjuster may be considered so that interference and rubbing with the neighbouring fingers is avoided or limited.

The rotatable adjuster may also have a harder or tougher core, for example, being metal, which may be covered by a material having a different hardness or toughness, for example, a plastics. This would be beneficial in preventing or limiting creep and wear during use, especially if the rotatable adjuster relies on a factional fit to prevent or limit angular displacement.

Although a strut element is preferably utilised on each side of the finger, a single strut element may be utilised on only one side. In this case, the pin elements may be screw- threaded fasteners. In any event, modifications to the pin elements may be incorporated in any embodiment, such as screw-threading so that the pin elements do not, for example, have to extend completely through the digit.

It is therefore possible to provide a finger fixator which imparts dynamic fixation due to the resilient fiexibility of the pin elements and the adjustability in situ of the or each strut element, for example, via a rotatable adjuster. This all thereby achieves a reduction in recovery time. The digit can still be used whilst the damaged area is being dynamically biased apart. A longitudinally positively adjustable support via a cam or off-centre adjuster allows the pin elements through a finger to be flexed, thereby providing the damaged area some give whilst maintaining a separating force. It is also far simpler for a surgeon to apply the finger fixator of the present invention without requiring a great deal of skill and practise. It is also feasible to utilise the pin engagable element of the strut element as a drill guide.

The embodiments described above are provided by way of examples only, and various other modifications will be apparent to persons skilled in the field without departing from the scope of the invention as defined by the appended claims.

Claims

1. A dynamic finger fixator (10) comprising a two-part elongate strut element (12) and two pin engagable elements (14) spaced apart on the two-part elongate strut element (12), the two-part elongate strut element (12) including spacing- adjustment means (16) for selectively adjusting and setting a spacing between the two pin engagable elements (14).

2. A dynamic finger fixator (10) as claimed in claim 1, wherein a first said part of the strut element (12) includes a strut member (20), and a second said part includes a rotatable adjuster (32) forming at least part of the spacing-adjustment means (16) rotatably mounted on the strut member (20), the strut member (20) including a first said pin engagable element (14) and the rotatable adjuster (32) including a second said pin engagable element (14) which is off-centre on a body (22) of the rotatable adjuster (32).

3. A dynamic finger fixator (10) as claimed in claim 2, wherein the strut member (20) includes an opening (30) at or adjacent to one end thereof, and the rotatable adjuster (32) is complementarily shaped to be rotatably mounted in the opening (30).

4. A dynamic finger fixator (10) as claimed in claim 3, wherein the rotatable adjuster (32) is a friction fit within the opening (30) of the strut member (20).

5. A dynamic finger fixator (10) as claimed in any one of claims 2 to 4, wherein the first pin engagable element (14) on the strut member (20) includes a plurality of first pin-receivable apertures (28) through a body (22) of the strut member (20).

6. A dynamic finger fixator (10) as claimed in claim 5, wherein the first pin- receivable apertures (28) are spaced apart along at least a portion of the longitudinal extent of the strut member (20).

7. A dynamic finger fixator (10) as claimed in claim 6, wherein the first pin- receivable apertures are spaced apart along a majority of the longitudinal extent of the strut member (20).

8. A dynamic finger fixator (10) as claimed in any one of claims 2 to 7, wherein the second pin engagable element (14) on the rotatable adjuster (32) includes a plurality of second pin-receivable apertures (34) through the body (22) of the rotatable adjuster (32).

9. A dynamic finger fixator (10) as claimed in claim 8, wherein the second pin- receivable apertures (34) are equi-angularly spaced apart on the body of the rotatable adjuster (32).

10. A dynamic finger fixator (10) as claimed in any one of claims 2 to 9, wherein the rotatable adjuster (32) is cylindrical.

11. A dynamic finger fixator (10) as claimed in any one of claims 2 to 9, wherein the rotatable adjuster is frusto-conical forming a taper fit with the strut member.

12. A dynamic finger fixator (10) as claimed in any one of claims 2 to 1 1 , further comprising indexing means for indexing the rotatable adjuster (32) on the strut member (20).

13. A dynamic finger fixator (10) as claimed in claim 12, wherein the indexing means includes a plurality of first teeth on the strut member (20) and a plurality of second teeth on the rotatable adjuster (32), the respective teeth interdigitating to hold an angular position of the rotatable adjuster (32) relative to the strut member (20).

14. A dynamic finger fixator (10) as claimed in any one of claims 2 to 13, further comprising a second two-part elongate strut element (12) having further said pin engagable elements (14), the first and second two-part elongate strut elements (12) being interconnectable about a patient's finger.

15. A dynamic finger fixator (10) as claimed in claim 14, further comprising first and second pin elements (18), the first pin element (18) extending from a first said pin engagable element (14) to the opposing pin engagable element (14), and the second pin element (18) extending from a second said pin engagable element (14) to its opposing pin engagable element (14).

16. A dynamic finger fixator (10) as claimed in claim 15, wherein the first and second pin elements (18) are resiliently flexible.

17. A dynamic finger fixator (10) as claimed in any one of claims 2 to 16, further comprising a rotation tool (38) for rotating the rotatable adjuster (32), the tool (38) including a head (40) and an elongate handle (42), the head (40) having engagement means (44) for releasably engaging the second pin engagable element (14).

18. A dynamic finger fixator (10) as claimed in claim 17, wherein the engagement means includes at least two spaced-apart pins (44) receivable in the second pin engagable element (14).

19. A dynamic finger fixator (10) as claimed in claim 1, wherein the two-part strut element (12) comprises interengagable rigid first and second strut members (20), each strut member (20) including a body (22) having a head (46), two spaced- apart legs (48) extending in parallel with each other from the head (46), and a cross member (50) interconnecting the legs (48) partway along their longitudinal extent.

20. A dynamic finger fixator (10) as claimed in claim 19, wherein the spacing- adjustment means (16) includes two sets of teeth (54), each strut member (20) having one said set of teeth (54) interengagable with the other said set of teeth (54) of the other strut member (20) to prevent or limit unintended longitudinal displacement.

21. A dynamic finger fixator (10) as claimed in claim 20, wherein the said teeth (54) are provided along at least one said leg (48) of each strut member (20).

22. A dynamic finger fixator (10) as claimed in claim 21, wherein two rows of said teeth (54) are provided, each row extending along one said leg (48) of each strut member (20).

23. A dynamic finger fixator (10) as claimed in any one of claims 20 to 22, wherein the head (46) of each strut member (20) includes further teeth (54) interengagable with further teeth (54) on the head (46) of the other strut member (20) to prevent or limit unintentional longitudinal displacement.

24. A dynamic finger fixator (10) as claimed in any one of claims 20 to 23, wherein each tooth (54) is angled towards a distal end of the associated leg (48) and away from the head (46).

25. A dynamic finger fixator (10) as claimed in any one of claims 20 to 24, wherein the spacing-adjustment means (16) further includes a fastener (62) for releasably fastening the first and second strut members (20) together whereby at least a portion of the respective teeth (54) interengage to prevent or limit unintentional longitudinal displacement.

26. A dynamic finger fixator (10) as claimed in claim 25, wherein a body (22) of at least one said strut members (20) includes a longitudinal channel (58) on an outwardly facing surface for receiving a head (46) of the fastener (62), so as to be at least in part recessed.

27. A dynamic finger fixator (10) as claimed in claim 25 or claim 26, wherein the cross member (50) of each strut member (20) is adapted to form a stop for the fastener (62), so as to prevent or limit excessive relative longitudinal displacement.

28. A dynamic finger fixator (10) as claimed in any one of claims 19 to 27, wherein the head (46) of each strut element (12) includes a said pin engagable element

29. A dynamic finger fixator (10) as claimed in claim 28, wherein each said pin engagable element (14) includes at least one pin-receivable aperture (72) through the respective head (46) of the strut element (12).

30. A dynamic finger fixator (10) as claimed in any one of claims 19 to 29, further comprising a second two-part elongate strut element (12) having further said pin engagable elements (14), the first and second two-part elongate elements being interconnectable about a patient's finger.

31. A dynamic finger fixator (10) as claimed in claim 30, further comprising first and second pin elements (18), the first pin element (18) extending from a first said pin engagable element (14) to the opposing pin engagable element (14), and the second pin element (18) extending from a second said pin engagable element (14) to its opposing pin engagable element (14).

32. A dynamic finger fixator (10) as claimed in claim 31 , wherein the first and second pin elements (18) are resiliently flexible.

33. A dynamic finger fixator (10) as claimed in claim 1, wherein the two-part strut element (12) comprises interengagable first and second strut members (20), each strut member (20) including an elongate body (22) and a saddle member (78) extending laterally of the body (22) at or adjacent to a distal end thereof, a said pin engagable element (14) being provided at or adjacent to distal ends of each saddle member (78).

34. A dynamic finger fixator (10) as claimed in claim 33, wherein each saddle member (78) comprises two spaced-apart arms (80) adapted to extend either side of a patient's finger.

35. A dynamic finger fixator (10) as claimed in claim 34, wherein each arm (80) is at least in part arcuate.

36. A dynamic finger fixator (10) as claimed in any one of claim 33 to 35, wherein the spacing-adjustment means (16) includes a releasable fastener and at least one slot in a body (22) of one said strut member (20), proximal portions of the bodies being overliable whereby the fastener in the slot is engagable with the lower body (22).

37. A dynamic finger fixator (10) as claimed in claim 36, wherein the spacing- adjustment means (16) includes teeth on at least the proximal portion of the body (22) of each strut member (20), the strut members (20) being interengagable via the respective teeth to prevent or limit unintentional longitudinal displacement.

38. A dynamic finger fixator (10) as claimed in any one of claims 33 to 37, wherein each said pin engagable element (14) includes at least two pin-receivable apertures (72).

39. A dynamic finger fixator (10) as claimed in any one of claims 33 to 37, further comprising first and second pin elements (18), the first pin element (18) being receivable by a first said pin engagable element (14) to extend across a first said saddle member (78), and the second pin element (18) being receivable by a second said pin engagable element (14) to extend across a second said saddle member (78).

40. A dynamic finger fixator (10) as claimed in claim 39, wherein the first and second pin elements (18) are resiliently flexible.

41. A dynamic finger fixator (10) comprising a two-part elongate strut element (12) and two pin engagable elements (14) spaced apart on the two-part elongate strut element (12), the two-part elongate strut element (12) including spacing- adjustment means (16) for selectively adjusting and setting a spacing between the two pin engagable elements (14) in situ, a first said part of the strut element (12) including a strut member (20), and a second said part being or including a rotatable adjuster (32) forming at least part of the spacing-adjustment means (16), the strut member (20) including a first said pin engagable element (14) and the rotatable adjuster (32) including a second said pin engagable element (14) which is off-centre on the rotatable adjuster (32), so that dynamic fixation is impartable to a patient's finger.

42. A dynamic finger fixator (10) as claimed in claim 41 , wherein the rotatable adjuster (32) is rotatably mounted on the strut member (20).

43. A dynamic finger fixator (10) as claimed in claim 4 or claim 42, wherein the strut member (20) includes an opening (30) at or adjacent to one end thereof, and the rotatable adjuster (32) is complementarily shaped to be rotatably mounted in the opening (30).

44. A dynamic finger fixator (10) as claimed in claim 43, wherein the rotatable adjuster (32) is a friction fit within the opening (30) of the strut member (20).

45. A dynamic finger fixator (10) as claimed in any one of claims 41 to 44, wherein the first pin engagable element (14) on the strut member (20) includes a plurality of first pin-receivable apertures (28) through a body (22) of the strut member (20).

46. A dynamic finger fixator (10) as claimed in claim 45, wherein the first pin- receivable apertures (28) are spaced apart along at least a portion of the longitudinal extent of the strut member (20).

47. A dynamic finger fixator (10) as claimed in claim 46, wherein the first pin- receivable apertures are spaced apart along a majority of the longitudinal extent of the strut member (20).

48. A dynamic finger fixator (10) as claimed in any one of claims 41 to 47, wherein the second pin engagable element (14) on the rotatable adjuster (32) includes a plurality of second pin-receivable apertures (34) through the body of the rotatable adjuster (32).

49. A dynamic finger fixator (10) as claimed in claim 48, wherein the second pin- receivable apertures (34) are equi-angularly spaced apart on the body of the rotatable adjuster (32).

50. A dynamic finger fixator (10) as claimed in any one of claims 41 to 49, wherein the rotatable adjuster (32) is or is substantially cylindrical.

51. A dynamic finger fixator (10) as claimed in any one of claims 41 to 50, further comprising indexing means for indexing the rotatable adjuster (32) on the strut member (20).

52. A dynamic finger fixator (10) as claimed in claim 51 , wherein the indexing means includes a plurality of first teeth on the strut member (20) and a plurality of second teeth on the rotatable adjuster (32), the respective teeth interdigitating to hold an angular position of the rotatable adjuster (32) relative to the strut member (20).

53. A dynamic finger fixator (10) as claimed in any one of claims 41 to 52, further comprising a second two-part elongate strut element (12) having further said pin engagable elements (14), the first and second two-part elongate elements being interconnectable about a patient's finger.

54. A dynamic finger fixator (10) as claimed in claim 53, further comprising first and second pin elements (18), the first pin element (18) extending from a first said pin engagable element (14) to the opposing pin engagable element (14), and the second pin element (18) extending from a second said pin engagable element (14) to its opposing pin engagable element (14).

55. A dynamic finger fixator (10) as claimed in claim 54, wherein the first and second pin elements (18) are resiliently flexible.

56. A dynamic finger fixator (10) as claimed in any one of claims 41 to 52, wherein the two-part elongate strut element (12) is the sole strut element (12) and in use extends along one side of a patient's digit.

57. A dynamic finger fixator (10) as claimed in any one of claims 41 to 56, further comprising a rotation tool (38) for rotating the rotatable adjuster (32), the tool (38) including a head (40) and an elongate handle (42), the head (40) having engagement means (44) for releasably engaging the second pin engagable element (14).

58. A dynamic finger fixator (10) as claimed in claim 57, wherein the engagement means (44) includes at least two spaced-apart pins receivable in the second pin engagable element (14).